Timing belt change is CRITICAL! 140K miles is the next due date for your car. Did the dealer throw this in also? Check to make sure the oil really was changed. Some dealers have been known to fake it. Check the tranny fluid for signs of burning.

Do you have any notes or receipts on previous maintenance? If no, assume the minimum was done. I suggest you:
1. Change all fluids (brake, transmission, antifreeze) immediately. Use stock Volvo chemicals and use distilled water with the antifreeze.
2. Check hoses for cracks and hardening and replace as needed. If they are original, it might be a wise precaution to change all of them.
3. Inspect brakes! If in doubt, replace the flexible brake lines, pads, etc. Don't take any chances with brakes.
Good luck and enjoy.

The owners manual should have a suggested maintenance schedule
Things I consider important.
Change oil often.
Always let the engine idle down prior to shutting off.
Pay close attention to tire pressure.
Find out if the 0-2 sensor or timing belt have ever been changed.
Every couple of years flush out cooling system,brake fluid and trans(if automatic).